Field of the Invention
The invention starts from an iron-nickel superalloy of the type IN 706. The invention also relates to a process for the production of a body of material stable at high temperatures from a starting body formed from this alloy.
Iron-nickel superalloys of the type IN 706 are distinguished by high strength at temperatures of around 700.degree. C. and are therefore used with advantage in heat engines such as, in particular, gas turbines. The composition of the alloy IN 706 can fluctuate within the limiting ranges given below:
max. 0.02 carbon PA1 max. 0.10 silicon PA1 max. 0.20 manganese PA1 max. 0.002 sulfur PA1 max. 0.015 phosphorus PA1 15 to 18 chromium PA1 40 to 43 nickel PA1 0.1 to 0.3 aluminum PA1 max. 0.30 cobalt PA1 1.5 to 1.8 titanium PA1 max. 0.30 copper PA1 2.8 to 3.2 niobium PA1 remainder iron. PA1 solution annealing of the starting body at a temperature of 980.degree. C. for a period of 1 h, PA1 cooling of the solution-annealed starting body with air, PA1 precipitation hardening at a temperature of 840 for a period of 3 h, PA1 cooling with air, PA1 precipitation hardening at a temperature of 720.degree. C. for a period of 8 h, PA1 cooling at a cooling rate of about 55.degree. C./h to 620.degree. C., precipitation hardening at a temperature of 620.degree. C. for a period of 8 h and cooling with air or solution annealing of the starting body at temperatures around 900.degree. C. for 1 h, PA1 cooling with air, PA1 precipitation hardening at 720.degree. C. for a period of 8 h, PA1 cooling at a cooling rate of about 55.degree. C./h to 620.degree. C., precipitation hardening at 620.degree. C. for 8 h and cooling with air.